The sum of 6 consecutive even numbers is 126

Since they are 6 consecutive even numbers, they will alternate odd/even/odd/even.
x, x+2, x+4, x+6, x+8, x+10 = 126
Simplify
6x + 30 = 126
6x = 96
x = 16
And you want the fourth number, so plug the x value back into the equation of 'x+6' and you will get 16+6 which = 22.

This can be put into a formula like so:
Since they are 6 consecutive even numbers, they will alternate odd/even/odd/even.
x, x+2, x+4, x+6, x+8, x+10 = 126
Simplify
6x + 30 = 126
6x = 96
x = 16
And you want the fourth number, so plug the x value back into the equation of 'x+6' and you will get 16+6 which = 22.